This is a collaborative study of the course and antecedents of functional decline in geriatric patients with schizophrenia. Functional (i.e., social, occupational, self-care, and independent living) impairment is one of the primary factors that influences both quality of life and societal cost of schizophrenia, with some evidence suggesting that some older patients with schizophrenia experience functional decline in later life. While in other illnesses such as dementia and head trauma it is clear that cognitive decline is an antecedent to functional decline, evidence regarding the correlates of functional status in schizophrenia is largely cross-sectional. The present study adopts a longitudinal approach to determine if the cross-sectional relationships between cognitive and functional deficits are the result of cognitive decline being an antecedent of functional decline. The results of previous studies regarding cognitive and functional decline are contradictory, with the Mt. Sinai group studying older and sicker patients finding decline and the UCSD group finding no evidence of decline in similar time periods. In order to determine if these discrepancies are due to differences in subject samples or the methods employed, the Mt. Sinai group will employ both their previous methods and those of the UCSD group in this study. Samples of healthy controls and ambulatory older schizophrenia patients who vary in their lifetime history of course of illness will be followed for 5 years and examined with performance-based measures of functional skills, assessments of cognitive functioning, and clinical symptom ratings. Sophisticated data analytic techniques will be employed to determine the course of functional changes, their temporal relationships with changes in cognitive and functional status, and their association with lifetime illness history. Findings from this study will clarify the course of functional status in schizophrenia and the timing of cognitive and functional changes. The results will also inform research on the biological basis of functional change in schizophrenia, as well as research on treatment of the illness. In a much-neglected area, the study of schizophrenia in late life, this research will focus on an aspect of the illness (the course of functional status) that has been studied for 100 years, but is still not well understood. [unreadable] [unreadable]